Our Submerged Past: Exploring Inundated Late Pleistocene (10,600 - 17,000 years ago) Caves in Southeast Alaska with Sunfish

May 15-June 4, 2022 / May 24-June 10, 2023

SUNFISH® Autonomous Underwater Vehicle

Expedition Overview

From May 24-June 10, 2023, a team of Indigenous Alaskans, local community members, and scientists explored the continental shelf west of Prince of Wales Island in southeast Alaska, as the second part of a multi-year project. Their goal was to locate and explore submerged caves and rock shelters that would have been accessible to early inhabitants of the region.

The team searched for submerged caves and rock shelter entrances using the SUNFISH® autonomous underwater vehicle (AUV) from aboard Fishing Vessel Showtime. This second part of the expedition project to explore southeast Alaska within the United States Exclusive Economic Zone followed an initial survey in May-June 2022 to identify target areas of interest for further exploration. Since the location of these submerged caves and rock shelters on the continental shelf places them closer to the coastlines of late Pleistocene Alaska (10,600 - 17,000 years ago), the project had the potential to transform our understanding of how and when people migrated to the Americas.

In 2023, the expedition team returned to areas identified in side-scan sonar last year to confirm whether features in the data represent true cave entrances or rock shelters. The team used the SUNFISH® vehicle to investigate these features and gathered detailed multibeam and camera data that was processed into maps. After reviewing this detailed data, an experienced dive team used the maps to perform sampling of targeted sites, bringing back sediment that was analyzed by the archaeology team.

New caves identified during the project were named by the local southeast Alaskan communities to honor the significance of these sites to their heritage. Archaeological locations were recorded and submitted to the Alaska Office of History and Archaeology. The data generated by this project was archived at the data warehouse of NOAA’s National Centers for Environmental Information.

Our Submerged Past adopted what is known as “Two-Eyed Seeing” as the guiding principle of operation to bring together western and Indigenous knowledge and ways of knowing. Members of the team represent local Indigenous knowledge including Haida and Tlingit, local fishing and community knowledge, and western science. Together, the team worked to build a better understanding of our past.

During the first year of the Our Submerged Past: Exploring Inundated Late Pleistocene (10,600 - 17,000 years ago) Caves in Southeast Alaska with Sunfish expedition, the expedition team surveyed the region using side-scan sonar and then investigate underwater anomalies identified during the surveys using remotely operated vehicle SeaDrone Inspector, pictured here, in order to locate submerged entrances to ancient caves and rock shelters that can be explored during the second year of the expedition. — During the first year of the Our Submerged Past: Exploring Inundated Late Pleistocene (10,600 - 17,000 years ago) Caves in Southeast Alaska with Sunfish expedition, the expedition team surveyed the region using side-scan sonar and then investigated underwater anomalies identified during the surveys using remotely operated vehicle SeaDrone *Inspector*, pictured here, in order to locate submerged entrances to ancient caves and rock shelters that could be explored during the second year of the expedition. *Image courtesy of SeaDrone Inc.* Download largest version (jpg, 2.5 MB).

During the second year of the Our Submerged Past expedition, the team used the SUNFISH® autonomous underwater vehicle to explore submerged caves and rock shelters discovered during the first year of the project. *Image courtesy of Jill Heinerth, Stone Aerospace.* Download largest version (jpg, 1.4 MB).

View of sunset (west) from Shipley Bay on the west side of Kosciusko Island (northern half of Prince of Wales Island) from June 2010. *Image courtesy of Kelly Monteleone.* Download largest version (jpg, 942 KB).

Operations

Map of Our Submerged Past expedition study area in southeast Alaska’s Alexander Archipelago. *Map created by Kelly Monteleone.* Download largest version (jpg, 6.9 MB).

Education Themes

Education theme pages provide the best of what the NOAA Ocean Exploration website has to offer to support your classroom during this expedition. On each theme page, you will find links to expedition features, lessons, multimedia, career information, and associated past expeditions.